9Ji

NMC ECommirned to Nuclear Excell~~ Palisades Nuclear Plant

Operated by Nuclear Management Company, LLC

July 28, 2005 10 CFR 54

U. S. Nuclear Regulatory CommissionATTN: Document Control DeskWashington, DC 20555

Palisades Nuclear PlantDocket 50-255License No. DPR-20

Response to NRC Requests for Additional Information Relating to License Renewaldated June 28. 2005

In letters dated June 28, 2005 (ML051790133, ML051790142, and ML051790157), theNuclear Regulatory Commission (NRC) requested additional information regarding theLicense Renewal Application for the Palisades Nuclear Plant. This letter responds tothose requests.

Enclosures 1, 2, and 3 provide the text of, and the NMC response to, each NRCrequest.

Please contact Mr. Darrel Turner, License Renewal Project Manager, at 269-764-2412,or Mr. Robert Vincent, License Renewal Licensing Lead, at 269-764-2559, if you requireadditional information.

Summarv of Commitments

This letter contains no new commitments or changes to existing commitments.

I declare under penalty of perjury that the foregoing is true and correct. Executed onJuly 28, 2,9057

Paul A. HardenSite Vice President, Palisades Nuclear PlantNuclear Management Company, LLC \-Y\a

27780 Blue Star Memorial Highway * Covert, Michigan 49043-9530Telephone: 269.764.2000

Enclosures (3)

cc Administrator, Region Ill, USNRCProject Manager, Palisades, USNRCResident Inspector, Palisades, USNRCLicense Renewal Project Manager, Palisades, USNRC

27780 Blue Star Memorial Highway * Covert, Michigan 49043-9530Telephone: 269.764.2000

ENCLOSURE 1

NMC Responses to NRC Requests for Additional Information (ML051790133)Dated June 28, 2005

(3 Pages)

Enclosure 1NMC Responses to NRC Requests for Additional Information (ML051790133)

dated June 28, 2005

RAI 3.5.2-1 -1

In Table 3.5.2-1 (Page 3-311), under the component type "Flood Barrier-Carbon Steel,Protected," PNP's Structural Monitoring Program is credited to manage the loss of leaktightness aging effect of flood doors. The Structural Monitoring Program is also creditedto manage the loss of leak tightness effect in: (1) HELB doors (Table 3.5.2-1, Page 3-313); (2) Control room vestibule door (Table 3.5.2-2, Page 3-314); (3) Flood doors andhatch (Table 3.5.2-10, Page 3-389); and (4) Control room vestibule door (Table 3.5.2-10, Page 390). Summarize past PNP's operating/inspection experience in managing theleak tightness of the above listed PNP components, and discuss specific provision(s) ofthe Structural Monitoring Program that are intended to maintain the leak tightnessjunction of the PNP components.

NMC Response to NRC RAI 3.5.2-1-1

For the flood doors, hatch, and High Energy Line Break / Moderate Energy Line Breakdoors, the Structural Monitoring Program credits an existing watertight barrier inspectionprocedure, MSM-M-16, "Inspection of Watertight Barriers". The watertight barrierinspection procedure is currently performed on a yearly basis on all watertight barriersas well as twice every refueling outage on high use doors. Parameters inspectedinclude seals (including performance of a chalk test), loose or missing parts, latchtightness, etc. A review of work order history identifies instances where the programhas found barrier seals that failed chalk tests and latches that were discovered to beloose. Repairs were made and the barriers were retested satisfactorily.

For the control room vestibule doors, the Structural Monitoring Program creditsPalisades' monthly Technical Specification Test MO-33, "Control Room VentilationEmergency Operation". One of the acceptance criteria is to ensure the control roompressure readings are equal to or greater than 0.125 inches of water as required byTechnical Specification Surveillance Requirement SR 3.7.10.4. Review of actionrequests indicates that this test has found and repaired a degraded vestibule doorclosing mechanism that had impacted its leak tightness.

I

Enclosure 1NMC Responses to NRC Requests for Additional Information (ML051790133)

dated June 28, 2005

RAI 3.5.2-2-1 (a)

Table 3.5.2-2 (Page 3-318) of the LRA credits ASME Section Xl IWB, IWC, IWD, IWFInservice Inspection Programs to manage loss of material aging effect of AuxiliaryBuilding cast iron components (ASME Class 2 & 3 Piping & Mechanical ComponentSupport). Table 3.5.2-2 (Page 3-336) of the LRA credits Structural Monitoring Programto manage loss of material aging effect of Discharge Structure Cast Iron components(Non-ASME Piping & Mechanical Component Support). Note 582 referred to by thetables states that cast iron is considered consistent with carbon steel and is evaluatedthe same, but with the additional aging effect/mechanism of loss of material due toselective leaching also evaluated. Discuss PNP's past operating experience andinspection results related to selective leaching of PNP's in-scope cast iron components.Did any of these affected cast iron components experience cracking or loss of functionas a result of leaching? If yes, summarize PNP's corrective action(s) taken to disposethe identified aging degradation.

NMC Response to NRC RAI 3.5.2-2-1(a)

The ASME and Non-ASME Cast Iron components in question are pump support skidslocated in the Auxiliary Building and in the Warm Water Recirculation Pump Houseabove the Discharge Structure. Both are in an indoor air environment. As indicated innote 582, both sets of components were evaluated for loss of material due to selectiveleaching. The results of those evaluations are that loss of material due to selectiveleaching does not apply to these components in their plant indoor air environment.Thus, the ASME Section XI IWB, IWC, IWD, IWF Inservice Inspection Program and theStructural Monitoring Program are only being credited for age managing loss of materialdue to general corrosion, not for loss of material due to selective leaching.

Where loss of material due to selective leaching does apply, namely in a wettedenvironment, the One Time Inspection Program is the appropriate program to managethe aging effect. Since the One Time Inspection Program is a new program (see LRASection B2.1.13), there is no operating experience or inspection results related toselective leaching on in-scope cast iron components.

It was noted, however, while reviewing the structural component types where loss ofmaterial due to selective leaching does apply in LRA Tables 3.5.2-5 (page 3-349) and3.5.2-7 (page 3-355), the One Time Inspection Program was not listed. These line itemsshould have credited the One Time Inspection Program for the aging management ofloss of material due to selective leaching, in addition to the Structural MonitoringProgram for management of other loss of material mechanisms. The resulting line itemrevisions are provided below. The existing table line item is shown in gray. The addedinformation is shown in bold text.

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Enclosure 1NMC Responses to NRC Requests for Additional Information (ML051790133)

dated June 28, 2005

Line Item Change for Discharge Structure Table 3.5.2-5 on page 3-349

ButldringFraming- Castiron Raw'A'ater(sluicegates )

St rUC! r' at

SUppoft forNon-SafetyRelated

's t SI!orn

a2,';'W%/ater(Ext I

Loss of SliucturalMaterial Montorlloq

II AG 2-a 351-22 580.582. A

Loss of One-Time III.A6.2-a 3.5.1-22 580,Material - Inspection 582. HSelectiveLeaching

Line Item Change for Intake Structure Table 3.5.2-7 on page 3-355

6uildinaFraming- CastIron RawWater(sluicegatrs ')

Structura! CastSupport for IronRegulatedEvents

R a'.Water(Ext I

Loss ofzt.A c r i

StructuraIrb,rnnitrnt i'ltn

lI A6 2-a 3 5 1 22 580r5p? A

StructuralSupport forSafetyRelated

Loss of One-Time IIU.A6.2-a 3.5.1-22 580,Material - Inspection 582. HSelectiveLeaching

3

ENCLOSURE 2

NMC Responses to NRC Requests for Additional Information (ML051790142)Dated June 28, 2005

(2 Pages)

Enclosure 2NMC Responses to NRC Requests for Additional Information (ML051790142)

dated June 28, 2005

RAI 3.5.2-4-1

In Table 3.5.2-4, under the component type "concrete protected," a number of structuralcomponents (e.g.,masonry walls, RC beams, columns, pedestals) are listed. It would belogical to have primary shield walls, secondary shield walls, and reactor pressure vessel(RPV) supports included under this component type. Section 3.5.2.2.2.1 describes theelevated temperature situation around the reactor vessel, and justifies the existence ofthe elevated temperatures in these areas, based on the estimated temperatures in thePalisades FSAR. The applicant is requested to provide the following information relatedto this component type.

RAI 3.5.2-4-1(a)

Please provide the operating experience related to the effectiveness of the "shieldcooling system." Are the shield wall temperatures, or any other parameter monitored,that would detect the malfunctioning of the cooling system?

NMC Response to NRC RAI 3.5.2-4-1 and 3.5.2-4-1(a)

In the 1995 Refueling Outage, an array of temperature monitoring devices was installedin the annulus between the reactor vessel and the biological shield wall. Ten of thesedevices were installed on the shield wall itself. Measurements showed temperaturesranging between 1640F and 2020F at the shield wall steel liner plate. These measuredtemperatures were used as input to the development of the revised biological shield walltemperature profiles shown in FSAR Figures 9-3, 9-4, 9-5 and 9-6. The results of thisbenchmarking analysis showed that the structural concrete in the biological shield wallremained below 1650F.

Shield wall temperatures are not continuously monitored. However, the shield coolingwater temperatures are monitored and will alarm in the control room when temperaturereaches 120 0F. Follow up actions to the alarm include commencing a plant shutdown ifthe alarm cannot be cleared and shield cooling return temperature exceeds 1650F.Similarly, shield cooling pump breakers are monitored and, should both shield coolingpumps trip, commencement of a plant shutdown is directed.

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Enclosure 2NMC Responses to NRC Requests for Additional Information (ML051790142)

dated June 28, 2005

RAI 3.5.2-4-1(b)

Based on the discussion of the elevated temperature condition, in and around theprimary shield wall in Section 3.5.2.2.2.1, the staff agrees with EPRI TR-103842, thatthe concrete properties will not be significantly affected, if the actual temperaturesaround the shield wall remain within the estimated limits. However, additional shrinkageand loss of moisture due to radiation could degrade the concrete on a long term basis.In this context, please provide a summary of the results of the last two inspectionsperformed for: (1) the primary shield wall, (2) RPV supports, (3) grouted anchorages,and (4) masonry walls inside the containment.

NMC Response to NRC RAI 3.5.24-1(b)

1 & 2) No inspection results are available. As discussed in section 2.4.4 of the LRA, theentire interior concrete surface of the Palisades Primary Shield Wall is lined with weldedcarbon steel plate. This includes the area around the reactor pressure vessel (RPV)supports. Accordingly, the shield wall concrete and the concrete around the RPVsupports are not accessible for inspection.

3) The term "grouted anchorage" in the description of "Building Framing - ContainmentCavity" in LRA Table 2.4.4-1 is used generically. The specific anchorage in the vicinityof the reactor shield wall is cast-in-place bolting or strap anchors, depending onelevation, for the liner plate. These anchors are not accessible for inspection.

4) There is one block wall inside containment on the 649' level, which is remote fromthe high temperature and radiation environment of the shield wall. Structural MonitoringProgram inspections were performed inside containment in 1996 and 1999. The top fivecourses of masonry wall blocks were found spalled at the northern most tip of the blockwall. The existing condition was determined not to be damaging to the masonry wallintegrity, which serves only as a partition wall. The condition was deemed acceptableas-is.

It should be noted that the concrete shielding blocks in the primary coolant pipeopenings of the shield wall that are mentioned in LRA Section 3.5.2.2.2.1 are notmasonry walls. These removable concrete blocks are held in place by externalrestraints without mortar, and are not inspected or evaluated as block walls.

2

ENCLOSURE 3

NMC Responses to NRC Requests for Additional Information (ML051790157)dated June 28, 2005

(12 Pages)

Enclosure 3NMC Responses to NRC Requests for Additional Information (ML051790157)

dated June 28, 2005

RAI A2.3-1

On Page A-3 of the LRA, the first two sentences in Section A2.3, Bolting IntegrityProgram, are not consistent with the FSAR Supplement in NUREG-1800 (e.g., Page3.1-23). Please clarify.

NMC Response to NRC RAI A2.3-1

The summary program description on LRA page A-3 is intended to describe thePalisades Bolting Integrity Program for all systems and components in the scope ofLicense Renewal. This description is intended to encompass the requirements forbolting integrity described in NUREG-1 800 page 3.3-17, 3.4-11, 3.5-19, 3.2-12 as wellas 3.1-23. Because there are slight differences in the various bolting programdescriptions in NUREG 1800, the Palisades program was more generally described in away that was intended to be consistent with all the NUREG 1800 descriptions. Inaddition, since the Palisades Bolting Integrity Program addresses structural bolting aswell as pressure retaining bolting, NMC did not limit the Palisades program scope byincluding the words "pressure retaining bolting" that appear in each NUREG-1800description. Finally, the reference to "enhanced inspection techniques" in NUREG 1800is not clearly coupled to the GALL NUREG 1801 XI.M18 "Bolting Integrity" programdescription, so this statement was not considered relevant to the Palisades programdescription.

Since the Palisades Bolting Integrity Program is consistent with the NUREG 1801,XI.M18, program description, it is concluded that its content is consistent with thedescription on page 3.1-23 of NUREG 1800.

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Enclosure 3NMC Responses to NRC Requests for Additional Information (ML051790157)

dated June 28, 2005

RAI B2.1.3-1

On Page B-25 of the LRA, the applicant states that the Structural Monitoring Program inLRA Section B2.1.19 is credited for the Palisades' Bolting Integrity Program. On PageB-29, the applicant states that structural bolting and fasteners are inspected visually inaccordance with the Structural Monitoring Program. However, bolting is not discussedin the Structural Monitoring Program. Please clarify why the Structural MonitoringProgram is credited for the Bolting Integrity Program when bolting is not explicitlydiscussed in the Structural Monitoring Program.

NMC Response to NRC RAI 82.1.3-1

While the summary description of the Structural Monitoring Program in LRA B2.1.19does not explicitly mention bolting, bolting is included in the program scope. Theprogram basis documentation for the Palisades Structural Monitoring Programspecifically states that structural bolting is inspected for indications of potential problemsincluding loss of coating integrity and obvious signs of corrosion, rust, etc.

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Enclosure 3NMC Responses to NRC Requests for Additional Information (ML051790157)

dated June 28, 2005

RAI B2.1.3-2

On Page B-25 of the LRA, the applicant states that the system monitoring program inLRA Section B2.1.20 is credited for the Bolting Integrity Program; however, bolting isnot mentioned in the system monitoring program. (1) Please clarify why the systemmonitoring program is credited for the Bolting Integrity Program when bolting is notdiscussed in the system monitoring program; (2) Under the system monitoring program,the applicant inspects piping systems visually to determine leakage during walkdowns.Most piping systems are covered with insulation. Discuss how bolting integrity (e.g.,cracking, loss of preload, and loss of material due to corrosion) would be determinedwhen bolts are covered with insulation.

NMC Response to NRC RAI B2.1.3-2

(1) Although Bolting is not specifically discussed in the LRA description of thePalisades System Monitoring Program, bolting is a component that will be inspected bythe program. The intent of the System Monitoring Program is to inspect all accessibleexternal surfaces of various component types (e.g., pump casings, valve bodies, piping,expansion joints), which would include bolted connections.

(2) NMC will not remove insulation solely for the inspections performed by the SystemMonitoring Program. Removal of insulation is not considered necessary to identify likelylocations of potential degradation. The condition of the insulation (e.g., discoloration,evidence of wetting, etc.), in itself, provides a good indirect indicator of the conditionsbeneath. If the insulation condition indicates that a potential problem exists beneath theinsulation, this condition would be documented and corrective action (e.g., isolation,insulation removal, further inspection, repairs) would be initiated.

The Palisades system walk downs will look for evidence of degradation where pipeinsulation is not removed in a manner similar to the ASME Code for safety-relatedpiping and components. The inspection performed under the Palisades SystemMonitoring Program of insulated non-Class 1 pipe and closure joints will be similar tothe visual examinations, VT-2, prescribed by the ASME Code for insulated Class 1piping and pressure retaining bolted connections. ASME Section Xl, Paragraph IWA-5242, Insulated Components, states, (a) For systems borated for the purpose ofcontrolling reactivity, insulation shall be removed from pressure retaining boltedconnections for visual examination VT-2. For other components, visual examinationVT-2 may be conducted without the removal of insulation by examining the accessibleand exposed surfaces and joints of the insulation. Essentially vertical surfaces ofinsulation need only be examined at the lowest elevation where leakage may bedetected. Essentially horizontal surfaces of insulation shall be examined at eachinsulation joint. (b) When examining insulated components, the examination ofsurrounding area (including floor areas or equipment surfaces located underneath thecomponents) for evidence of leakage, or other areas to which such leakage may bechanneled, shall be required. (c) Discoloration or residue on surfaces examined shall

3

Enclosure 3NMC Responses to NRC Requests for Additional Information (ML051790157)

dated June 28, 2005

be given particular attention to detect evidence of boric acid accumulation from boratedreactor coolant leakage.

Management of loss of bolting pre-load is addressed by maintenance and installationprocedures. Loss of material due to corrosion will be identified by discovering theevidence of leakage prior to a loss of intended function. For cracking to occur threeconditions must be present: high stress, a corrosive environment, and susceptiblematerial. A corrosive environment is precluded through use of proper lubricants, andproper bolt torquing practices. Should leakage occur, the evidence of the leak would bediscovered, investigated and resolved prior to a loss of intended function.

4

Enclosure 3NMC Responses to NRC Requests for Additional Information (ML051790157)

dated June 28, 2005

RAI B2.1.3-3

On Page B-25 of the LRA, the applicant states that the ASME Section Xl IWB, IWC,IWD, IWF Inservice Inspection (ISI) program in LRA Section B2.1.2 is credited for theBolting Integrity Program. The ASME Section Xl specifies periodic inserviceexamination on a sampling basis. Please clarify whether all bolts in the Palisades plantthat are covered under the LRA will be examined before entering extended period ofoperation. If not, provide a percentage of bolts that will be examined per the ISI programbefore entering extended period of operation and discuss whether this percentage issufficient to show bolting integrity of the entire bolting population.

NMC Response to NRC RAI B2.1.3-3

On page B-25 of the LRA, NMC states that the bolting integrity program credits activitiesperformed under three separate aging management programs for the inspection ofbolting. The three aging management programs are: (1) ASME Section Xi IWB, IWC,IWD, IWF Inservice Inspection (ISI) program, (2) Structural Monitoring Program, and (3)System Monitoring Program.

On page B-26 of the LRA, NMC describes the scope of the credited programs forbolting as:

* The ASME Section Xl IWB, IWC, IWD, IWF Inservice Inspection Programprovides the requirements for inservice inspection of ASME Class 1, 2, and 3piping, supports, and their integral attachments, which includes pressureretaining and support bolting. This program specifically discusses the inspectionand lubrication of the reactor vessel head closure studs. The programsupplements the ASME Section Xl (Code Case N491-2), Subsection IWFrequirements, by applying the inspection requirements of Subsection IWB,Category B-G-1 to high yield strength (>150 ksi) bolting used in Nuclear SteamSupply System (NSSS) component supports.

* The System Monitoring Program provides the requirements for the inspection ofnon-safety related bolting within the scope of license renewal.

* The Structural Monitoring Program provides the requirements for the inspectionof all structural bolting within the scope of license renewal. Other bolting andfasteners are also included within the scope of this program, such as those usedin supports for cable trays, conduits and cabinet supports.

All ASME class 1, 2, and 3 bolting is inspected by the ASME Section Xl IWB, IWC, IWD,IWF Inservice Inspection Program a minimum of once each ten year inspection interval.ASME Section Xl, Table IWB-2500-1 requires inspection of bolts, studs, and nuts forvarious class 1 components. In all cases, the inspection requirement encompasses allbolts, studs, and nuts each inspection interval. There is no provision for a samplingsize. ASME Section Xl, Table IWC-2500-1 requires inspection of 100 percent of boltsand studs of size two inch and greater at each bolted connection in class 2 components.

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Enclosure 3NMC Responses to NRC Requests for Additional Information (ML051790157)

dated June 28, 2005

IWC-2500-1 also requires a visual VT-2 examination of all pressure retainingcomponents during a system leakage test. The leakage test is required each inspectionperiod. ASME Section XI, Table IWD-2500-1 requires a visual VT-2 examination of thepressure retaining boundary of class 3 systems during a system leakage test eachinspection period.

Non-ASME classed bolting within the scope of license renewal that is reasonablyaccessible for external visual inspection will be periodically inspected under either theSystem Monitoring Program (system walkdowns) or the Structural Monitoring Program(general area inspections).

Each of these programs currently exists. The LRA includes commitments for certainenhancements to make each program an effective aging management program.Enhancements to the bolting integrity program will be implemented prior to the periodof extended operation. Upon completion of the identified enhancements, all boltingrequiring aging management for license renewal will be included in an appropriate agingmanagement program, and a sufficient percentage of the total population will beaccessible for inspection to provide reasonable assurance that bolting condition isadequate.

6

Enclosure 3NMC Responses to NRC Requests for Additional Information (ML051790157)

dated June 28, 2005

RAI B2.1.3-4

On Page B-26 of the LRA, the applicant states that the attributes of the Bolting IntegrityProgram are adequate to manage loss of preload without hot torquing; therefore, hottorquing to establish a preload will not be credited for aging management of bolting. Theapplicant needs to explain in detail which attributes of the Bolting Integrity Program areadequate to manage loss of preload without hot torquing.

NMC Response to NRC RAI B2.1.3-4

Consistent with the recommendations in EPRI TR-104213s, Bolted Joint Maintenanceand Applications Guide, NMC has assessed the various aspects of proper preloadingpractices, including the potential benefits versus risks of hot torquing. Based on theseconsiderations, it has been concluded that Palisades' fastener preload practices andprocedures are sufficient to assure bolted joint integrity without the inclusion of hottorquing requirements. Several key attributes of those practices and procedures aredescribed below.

Palisades' fastener preload procedures include instructions for preparation of joints andpredetermination of fastener size, material, thread lubricant and design temperature.Yield strength, thread stress areas and nut factors are determined. Final torque,maximum torque and torque for each pass is calculated. Torque is generally applied ina minimum of four passes, and measured during the sequence. Gasket compressionthicknesses are determined as part of the preload procedure. Gaskets are crushedprogressively, in stages, and standard bolt patterns are used to crush gaskets uniformly.

Therefore, the combination of the maintenance and installation practices and theperiodic inspections conducted under the Bolting Integrity Program are sufficient tomanage loss of bolting preload.

7

Enclosure 3NMC Responses to NRC Requests for Additional Information (ML051790157)

dated June 28, 2005

RAI B2.1.3-5

On Page B-26 of the LRA, the applicant states that "...The Bolting Integrity Program isconsistent with NUREG-1801, Section XI.M18, Bolting Integrity." The applicant alsostates that -2- "...Two enhancements are planned to bring the Bolting Integrity Programinto conformance with the NUREG-1 801 program description..." These two statementsseem to contradict each other. Please clarify.

NMC Response to NRC RAI B2.1.3-5

These statements are not inconsistent. LRA Section B1.1, Overview and Methods ofDiscussion, discuss the NMC philosophy applied to the LRA concerning enhancementsand exceptions to NUREG 1801 program descriptions. LRA page B-1 states, "Programenhancements are identified for some of the existing programs that will bring theprograms into conformance with NUREG 1801. Each program in this appendix isdescribed as if the identified enhancements have been implemented."

All the enhancements identified in the LRA Appendix B program descriptions have alsobeen listed as commitments in the LRA transmittal letter.

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Enclosure 3NMC Responses to NRC Requests for Additional Information (ML051790157)

dated June 28, 2005

RAI B2.1.3-7

On Page B-28 of the LRA, the applicant states that normal maintenance practices andquality verification procedures for pressure retaining bolting includes a check of bolttorque and uniformity of gasket compression. Discuss whether there are similarprocedures to verify the torque of structural bolting.

NMC Response to NRC RAI B2.1.3-7

There are similar procedures to verify the torque of structural bolting. MSM-M-45,"Removal, Installation, and Repair of Pipe Supports" provides criteria for proper torquingor retorquing of bolted connections related to pipe supports. MSM-M-44, "Hilti BoltInstallation and Inspection" provides instructions for installation and or retorquing of theHILTI brand Drop-In anchors, and installation and or retorquing of the HILTI brand KwikBolt II Anchors. Hilti Drop-in Anchors are used for mounting small items. Hilti Kwik Bolt11 Anchors may be used for piping , cable tray, HVAC, and small equipment supports aswell as electrical components and instrumentation. Torquing requirements for newconstruction or modifications would not necessarily be covered by permanent plantmaintenance procedures, but would be specified in new construction specifications ordrawings. Finally, procedure MSM-M-48 "Standard Torque Tables" is applied tofasteners in standard bolting applications on pressure retaining components, and it isavailable for use in structural applications in the absence of other guidance.

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Enclosure 3NMC Responses to NRC Requests for Additional Information (ML051790157)

dated June 28, 2005

RAI B2.1.3-8

On Page B-30 of the LRA, the applicant states that MC component support bolting isevaluated in accordance with the acceptance standards of ASME Code Case N-491-2,Section 3410. GALL XI.M18 recommends immediate replacement of the cracked boltwhen indications of cracking is found in support bolting. Code Case N-491-2 providesguidance on examination and acceptance criteria, but it does not specify replacement.Discuss whether the Bolting Integrity Program has a process by which a cracked boltwill be replaced immediately.

NMC Response to NRC RAI B2.1.3-8

If a degraded bolt is identified, the condition would be entered into the plant CorrectiveAction Program. The program, in turn, would require a prompt assessment of the effectof the condition on equipment operability and plant safety. Corrective actions would beassigned and completed commensurate with the safety and operational significance ofthe condition. The corrective action for a degraded bolt would likely include eventualreplacement of that bolt, but the timing of the replacement would have to consider thesafety-significance of the condition, the plant conditions needed to safely complete thework, the status of other plant equipment, the extent and complexity of repair,radiological conditions, availability of replacement parts, etc.

The most prudent action, therefore, could include immediate replacement as emergencymaintenance; or it could involve such things as isolation of the affected bolted joint fromoperating systems, analysis to verify adequate pressure boundary or structural integrity,later replacement using normal maintenance planning and scheduling procedures, etc.The timing and nature of any actions to be taken would be planned and managed underthe corrective action process in a way that best assures the safety of the public, plantworkers, and plant equipment.

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Enclosure 3NMC Responses to NRC Requests for Additional Information (ML051790157)

dated June 28, 2005

RAI B2.1.3-9

On Page B-30 of the LRA, the applicant states that "...Palisades Bolting IntegrityProgram makes no distinction regarding "immediate' repairs, but instead relies upon theplant inservice inspection program and corrective action process to evaluate, prioritizeand schedule repairs..." GALL XI.M18 recommends that immediate repairs beperformed for major leaks that may cause corrosion or contamination. Explain whethermajor leaks that are caused by degraded bolting will be repaired immediately, includingbolting replacement.

NMC Response to NRC RAI B2.1.3-9

If a major leak were to occur that had a significant impact on plant equipment or plantsafety, operators would take prompt action in accordance with procedures to bring theplant to a safe, stable condition. The leaking joint would be isolated if practical, or theplant could even be shut down and depressurized, if warranted. Actions for such asevere condition would not be delayed for administrative processing of corrective actiondocuments, etc. Longer term repairs and recovery actions would be managed underthe corrective action program.

Whether or not immediate operational actions are taken, degraded conditions would beentered promptly into the plant Corrective Action Program. The program, in turn, wouldrequire a prompt assessment of the effect of the condition on plant safety andequipment operability. Corrective actions would be assigned and completedcommensurate with the safety and operational significance of the condition. Thecorrective action for a degraded bolt would likely include eventual replacement of thatbolt, but the timing of the replacement would have to consider the safety-significance ofthe condition, the plant conditions needed to safely complete the work, the status ofother plant equipment, the extent and complexity of repair, radiological conditions,availability of replacement parts, etc.

The most prudent action, therefore, could include immediate replacement as emergencymaintenance; or it could involve such things as isolation of the affected bolted joint fromoperating systems, analysis to verify adequate pressure boundary or structural integrity,later replacement using normal maintenance planning and scheduling procedures, etc.The timing and nature of any actions to be taken would be planned and managed underthe corrective action process in a way that best assures the safety of the public, plantworkers, and plant equipment.

11

Enclosure 3NMC Responses to NRC Requests for Additional Information (ML051790157)

dated June 28, 2005

RAI B2.1.3-10

On Page B-31 of the LRA, the applicant states that the Bolting Integrity Program hasbeen effective in identifying six instances of bolting degradation at Palisades in a timelymanner. (1) Discuss how the six instances of bolting degradation were dispositioned; (2)Discuss how the six instances of bolting degradation were detected (e.g., by routinemaintenance, system walkdown, or leakage monitoring system); and (3) Describedegradation mechanism(s) of each of the six instances in question.

NMC Response to NRC RAI B2.1.3-10

There were two instances of corrosion of components in the Condensate Storage Tank,valve pit. A Corrective Action document was initiated after corrosion was identified oncarbon steel flanges during a valve line-up by operations. Another Corrective Actiondocument was initiated by engineering due to corroded bolts in a flange that werediscovered during a walk down in the valve pit. In both instances, the components werereplaced. Both of these instances were due to the unventilated damp environmentwithin the pit.

There were two Corrective Action documents initiated concerning boric acid wastage ofPrimary Coolant Pump flange bolts. This was discovered by System Engineering duringwalk down. The boric acid was removed and an engineering evaluation of the bolts wasperformed. The evaluation confirmed that the Primary Coolant Pumps remainedoperable (i.e., integrity was not compromised by the limited degradation of the boltingmaterial). The degraded bolts were subsequently replaced during the next refuelingoutage.

In addition to database searches, the Palisades License Renewal Project solicitedoperating experience from plant equipment experts. Specifically, plant experts wereasked, "What comments or documents would you suggest adding to the [Palisades OEIdatabase to highlight recurring aging issues that we might need to address in our AgingManagement Programs"? There were two bolting-related responses to this questionfrom system owners. One system engineer identified the possibility of fatigue of pipesupports, and another engineer identified the potential for boric acid wastage ofEngineered Safeguards System bolting material. Since both of these concerns werenon-specific, and were being addressed by a combination of TLAAs and AgingManagement Programs, no further action was required. No new aging mechanisms norfailures of aging management programs were identified.

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